Although inadequate growth is a very serious problem for infants, the early identification and management of this health problem is not well understood. The focus of this prospective, longitudinal study is on non-organic infant growth failure. Using a nursing epidemiological framework, growth failure is viewed as a result of multiple interacting risk factors, many of which are potentially amenable to change by nursing intervention. The specific aims of the study are: (1) to develop standards for determining growth failure in infants, (2) to examine the interrelatedness of physical, psychosocial, and sociocultural variables in explaining differences in infant growth, and (3) to develop a framework for a risk assessment tool for growth failure. A sample of 672 infants and their families will be recruited into the study by selecting six subjects per week over a 28 month period of time. Subjects will be selected from the nursing clinics of three community health settings in one Colorado county. Based on previous research, 53 of the infants who complete the 15 month study are expected to experience growth failure sometime during this period of their life. Data on all subjects will be obtained using multiple data collection methods including: monthly anthropometric measures; routine clinic visits (at 2, 4, 6, 9, 12, & 15 months of age); interviews, questionnaires, and observations during home visits (at 1, 4, 7, 10, & 14 months of age); and existing records. In addition to descriptive statistics and other preliminary procedures, analyses will be organized addressing the three aims. In Aim 1, predicted deviation growth scores will be explored in developing standards for determining growth failure. Structural equation modeling will be used in Aim 2 for developing a model to explain the occurrence of growth failure. Discriminant analysis using linear or logistic regression methods will be used in Aim 3 for developing the framework for a risk assessment tool. The findings of this study are expected to be very clinically relevant, contributing to identification and greater understanding of growth failure and its risk factors.